Epoxy resin compositions containing acid anhydride curing agents have heretofore been known to form transparent cured products that are suitable as sealing materials for optical semiconductor devices such as light-emitting diodes and photodiodes.
For example, epoxy resin compositions composed mainly of an epoxy resin having an organic resin skeleton, such as bisphenol A epoxy resin, bisphenol F epoxy resin, or (3′,4′-epoxycyclohexyl)methyl-3,4-epoxycyclohexane carboxylate, are used in the field of optical semiconductor devices.
The recent advance of the performance of optical semiconductors, however, has required sealing materials for optical semiconductor devices to have more excellent heat resistance, light resistance, and the like. In this respect, the conventionally known epoxy resin compositions have failed to produce sufficient properties.
In consideration of this problem, proposals have heretofore been made on resin compositions for use in various optical semiconductors.
For example, a thermosetting resin composition for use in optical semiconductors which is obtained by curing a particular silicone composition through hydrosilylation reaction has been proposed (see e.g., Patent Document 1).
A technique of applying a particular silicone composition having improved hardness to use in optical semiconductors has also been proposed (see e.g., Patent Document 2).
A composition for use in optical semiconductors containing organopolysiloxane having a particular structure has further been proposed (see e.g., Patent Document 3).
In addition, a technique of applying a methacryloxy group-containing silicone composition to use in optical semiconductors has been proposed (see e.g., Patent Document 4).
In addition, a technique of using an alicyclic epoxy compound and a vinyl ether compound in combination has been proposed as a technique of applying an epoxy resin composition to photosensitive coating materials, inks, and the like (see e.g., Patent Documents 5 and 6).
Furthermore, a technique of controlling the mechanical properties of a cured product by allowing a material containing an epoxy compound and a vinyl ether compound in combination to further contain a particular phenol resin has been proposed (see e.g., Patent Document 7).